Description: Flat grasslands and marshes hug the
coast of the Gulf of Mexico from northern Tamaulipas across the mouth
of the Río Grande up into the rice country of southeastern Texas
and southwestern Louisiana and across the great Louisiana marshlands
at the mouth of the Mississippi River. The Laguna Madre on both sides
of the border (an IBA in Mexico) is dominated by dunes, beaches, and
black mangroves. This BCR features one of the greatest concentrations
of colonial waterbirds in the world, with breeding Reddish Egret, Roseate
Spoonbill, Brown Pelican, and large numbers of herons, egrets, ibis,
terns, and skimmers. The region provides critical in-transit habitat
for migrating shorebirds, including Buffbreasted Sandpiper and Hudsonian
Godwit, and for most of the neotropical migrant forest birds of eastern
North America. Mottled Duck, Fulvous Whistling-Duck, and Purple Gallinule
also breed in wetlands, and winter numbers of waterfowl are among the
highest on the continent. These include dabbling ducks (especially Northern
Pintail and Gadwall), Redhead, Lesser Scaup, and White-fronted Geese
from both the Central and the Mississippi Flyways. The most important
waterfowl habitats of the area are coastal marsh, shallow estuarine
bays and lagoons, and wetlands on agricultural lands of the rice prairies.
Loss and degradation of wetland habitats due to subsidence, sea-level
rise, shoreline erosion, freshwater and sediment deprivation, saltwater
intrusion, oil and gas canals,and navigation channels and associated
maintenance dredging are the most important problems facing the areas
wetland wildlife.